Issue checkstyle#4393: ASTs to be generated and walked only when ther…

…e are corresponding type of checks. No parsing if no checks are specified
voidfist · Jun 5, 2017 · f4d2c0b · f4d2c0b
1 parent 45d5f97
commit f4d2c0b
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Showing 2 changed files with 47 additions and 11 deletions.
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java b/src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java
@@ -171,17 +171,23 @@ protected void processFiltered(File file, List<String> lines) throws CheckstyleE
             final String msg = "%s occurred during the analysis of file %s.";
             final String fileName = file.getPath();
             try {
-                final FileText text = FileText.fromLines(file, lines);
-                final FileContents contents = new FileContents(text);
-                final DetailAST rootAST = parse(contents);
-
-                getMessageCollector().reset();
-
-                walk(rootAST, contents, AstState.ORDINARY);
-
-                final DetailAST astWithComments = appendHiddenCommentNodes(rootAST);
-
-                walk(astWithComments, contents, AstState.WITH_COMMENTS);
+                if (!ordinaryChecks.isEmpty()
+                        || !commentChecks.isEmpty()) {
+                    final FileText text = FileText.fromLines(file, lines);
+                    final FileContents contents = new FileContents(text);
+                    final DetailAST rootAST = parse(contents);
+
+                    getMessageCollector().reset();
+
+                    if (!ordinaryChecks.isEmpty()) {
+                        walk(rootAST, contents, AstState.ORDINARY);
+                    }
+                    if (!commentChecks.isEmpty()) {
+                        final DetailAST astWithComments = appendHiddenCommentNodes(rootAST);
+
+                        walk(astWithComments, contents, AstState.WITH_COMMENTS);
+                    }
+                }
             }
             catch (final TokenStreamRecognitionException tre) {
                 final String exceptionMsg = String.format(Locale.ROOT, msg,

diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/TreeWalkerTest.java b/src/test/java/com/puppycrawl/tools/checkstyle/TreeWalkerTest.java
@@ -22,6 +22,13 @@
 import static com.puppycrawl.tools.checkstyle.checks.naming.AbstractNameCheck.MSG_INVALID_PATTERN;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.times;
+import static org.powermock.api.mockito.PowerMockito.doNothing;
+import static org.powermock.api.mockito.PowerMockito.mockStatic;
+import static org.powermock.api.mockito.PowerMockito.spy;
+import static org.powermock.api.mockito.PowerMockito.verifyPrivate;
+import static org.powermock.api.mockito.PowerMockito.when;
 
 import java.io.BufferedWriter;
 import java.io.File;
@@ -38,16 +45,23 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
 
 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.FileContents;
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 import com.puppycrawl.tools.checkstyle.checks.coding.HiddenFieldCheck;
 import com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocPackageCheck;
 import com.puppycrawl.tools.checkstyle.checks.naming.ConstantNameCheck;
 import com.puppycrawl.tools.checkstyle.checks.naming.TypeNameCheck;
 import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
 
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(TreeWalker.class)
 public class TreeWalkerTest extends BaseCheckTestSupport {
     @Rule
     public final TemporaryFolder temporaryFolder = new TemporaryFolder();
@@ -253,6 +267,22 @@ public void testRequiredTokenIsEmptyIntArray() throws Exception {
         }
     }
 
+    @Test
+    public void testBehaviourWithZeroChecks() throws Exception {
+        final String errMsg = "No checks -> No parsing";
+        final TreeWalker treeWalkerSpy = spy(new TreeWalker());
+        final Class<?> classAstState =
+                Class.forName("com.puppycrawl.tools.checkstyle.TreeWalker$AstState");
+        mockStatic(TreeWalker.class);
+        when(TreeWalker.parse(any(FileContents.class)))
+                .thenThrow(new IllegalStateException(errMsg));
+        doNothing().when(treeWalkerSpy, "walk",
+                any(DetailAST.class), any(FileContents.class), any(classAstState));
+        treeWalkerSpy.processFiltered(temporaryFolder.newFile("file.java"), new ArrayList<>());
+        verifyPrivate(treeWalkerSpy, times(0)).invoke("walk",
+                any(DetailAST.class), any(FileContents.class), any(classAstState));
+    }
+
     private static class BadJavaDocCheck extends AbstractCheck {
         @Override
         public int[] getDefaultTokens() {